html, body {
  height: 100%;
  width: 100%;
  margin: 0;
  font-family: Helvetica Neue, Lucida Grande, Segoe UI, Tahoma, sans;
  font-size: 16px;
  background: #EDEDED;
}

section {
  padding: 1em 1em 0;
}

section .buttons-group {
  margin-bottom: 1em;
}

section .buttons-group h5 {
  margin-top: 0;
  margin-bottom: 0.65em;
}

#output {
  margin-top: 20px;
  box-sizing: border-box;
  padding: 5px;
  font-size: 12px;
  font-family: Consolas, "Liberation Mono", Menlo, Courier, monospace;
  background: #fff;
  border: 1px solid #BEBEBE;
  height: 248px;
  max-height: 248px;
  overflow: auto;
}

#output span.error {
  color: red;
}